Constant delivery pump



June 7, 1966 o, ROSAEN 3,254,606

CONSTANT DELIVERY PUMP Filed Dec. 16, 1963 2 Sheets-Sheet 1 FIG. 2 45 INVENTOR.

NILS O. Ros/am jaw June 7, 1966 N. o. ROSAEN 3,254,606

CONSTANT DELIVERY PUMP Filed Dec. 16, 1963 2 Sheets-Sheet 2 32 k I INVEN TOR.

1 NILS O. ROSAEN United States Patent 3,254,606 CONSTANT DELIVERY PUMP Nils O. Rosaen, Bloomfield Hills, Mich. (1776 E. Nine Mile Road, Hazel Park, Mich.) Filed Dec. 16, 1963, Ser. No. 330,797 3 Claims. (Cl. 103-436) My invention relates to fluid pumps and more particularly to vane-type pumps having improved means for pressure-balancing the vanes.

In the vane pumps of the present invention, the vanes are slidably carried in slots provided around the periphery of a rotor and are guided for movement by a cam ring surrounding the rotor, so that the vanes will pump fluid from an'inlet to an outlet area provided between the cam ring and the rotor, all in a known manner.

Heretofore, such vanes have been pressure balanced end-to-end by admitting fluid pressure beneath them, which fluid pressure will generally approximate the pressure to which a beveled face at the outer end of each vane is subject. The outer end bevel will generally be on the leading edge, and the trailing edge will have only a small area which might be affected by pressure at the trailing side of the vane.

However, the effect of pressure at the trailing side is only minimized by such construction, and in some instances, where very high pressures are achieved, the small unbalance is enough to cause vane and cam ring damage and poor performance.

An object of the present invention is to improve such pumps by providing a more effective vane balance.

Another object of the invention is to increase the life and improve the performance of vane-type pumps by providing'means for separately balancing the leading and trailing portions of the vanes.

These and other objects of the invention will become apparent upon reference to the following description and the accompanying drawings illustrating a preferred embodiment of the invention in which like reference characters refer to like parts throughout the several views and in Which FIG. 1 is an elevational view of a preferred pump incorporating the present invention.

FIG. 2 is a longitudinal cross-sectional view of the pump taken substantially on the line 22 of FIG. 1.

FIG. 3 is a longitudinal cross-sectional view of the pump taken substantially on the line 3--3 of FIG. 2.

FIG. 4 is a transverse cross-sectional view of the pump taken substantially on the line 44 of FIG. 2.

FIG. 5 is an elevational view of the cam ring and rotor assembly of the pump as seen substantially from the line 55 of FIG. 2; and FIG. 6 is a perspective enlarged view of one .of the vanes incorporated in the present pump.

Description As disclosed, the preferred pump comprises a housing 10 having a chamber 11, an integral mounting plate 12, and a stepped shaft bore 13. The chamber 11 is closed by-an end cap 14 secured to the housing by any means such as screws 15.

A pair of cheek plates 16 and 17 are carried in the chamber 11, sandwiching between them a rotor 18 peripherally surrounded by a cam ring 19. The cheek plates 16 and 17 and cam ring 19 are preferably held together by screws 20 or the like for convenience in assembling.

The thereby enclosed rotor 18 is splined as at 21 to a drive shaft 22 carried by ball bearing assembly 23 retained in the bore 13 by any means such as a snap ring 24, and centered with the cheek plates by bearings 25 and 26.

3,254,606 Patented June 7, 1966 Fluid enters an intake passage 30 in the housing 10 from any suitable fluid source (not shown) and is directed into a channel 31 provided around the chamber 11, thence.

through shallow recesses 32 in the faces of the cheek plates adjacent the cam ring 19, into registering inlet recesses 33 in opposite faces of the cam ring 19, and into pumping chambers 34 which are formed by radial spacings between the cam ring periphery and the rotor periphery, as seen in FIG. 5. Intermediate the chambers 34 the cam ring is spaced close to the rotor periphery as at 35.

Outlet recesses 40 in the cam ring 19 are angularly spaced from the inlet recesses 33 and register with arcuate grooves 41 in the cheek plates, such that fluid, now under pressure as will be explained is passed to ports 42.

The ports 42 in cheek plate 16 register with ports 43 provided in the housing 10 which ports are sealed by O-rings 44, and fluid pressure is discharged through the,

' sides of the rotor 18.

The rotor 18, as best seen in FIG. 5, is cylindrical-and has substantially radial stepped slots 50 annularly spaced around the periphery and extending laterally from face to face. Vane elements 51 are slidably carried in the slots '50 and are stepped as shown to be substantially complementary to the slots 50.

As the rotor 18 turns, in a clockwise direction as seen in FIG. 5, the vanes 51 are guided by the contour of the cam ring inner periphery for radial sliding movement in the slots 50, thereby pumping fluid from the inlet recesses 33 through the pumping chambers 34 and out the outlet recesses 40. Intermediate the pumping chambers 34 the vanes 51 will be retracted into the slots 50, and in the vicinity of the pumping chambers 34 the vanes 51 will be extended as shown.

Construction of a vane 51 is shown in FIG. 6, as having beveled portions 52 and 53 at the outer end on, respectively, the leading and trailing sides of the vane 51. The vane is stepped as shown to provide aleading side inner end 54 and a trailing side inner end 55.

Between the beveled portions 52 and 53 is a cam follower edge 56. It will be apparent that at any period of operation except When the vane cam follower edge 56 is in an area of the cam ring contour not spanned by either the inlet recess 33 or the outlet recess 40, the beveled portion 52 will be subjected to a different pressure than the beveled portion 53. These pressures, whether discharge or suction, tend to unbalance the vanes. It is not new to admit pressure beneath a vane in an attempt to balance it, but heretofore to my knowledge such ideas have not been carried out to produce truly effective balancing because heretofore the different leading and trailing side pressures have not been taken. into account. Usually it is proposed to minimize such differences by bevelling only one side of the vane outer end, in the hope that the other side will not be greatly effected, but where high speed, high pressure pumps are involved, even slight imbalances will have a magnified effect.

In the present pump, as will hereafter be explained, I balance the leading and trailing sides of the vanes separately as follows:

Each cheek plate is provided with radial passages 60 open to the channels 31 as seen in FIGS. 2 and 4, and directing inlet or suction pressure to ports 61 which open to the sides of the cheek plates facing the rotor 18. Each 3 cheek plate is also provided with passages 62 as shown in FIG. 4, connecting the arcuate grooves 41 with ports 63 which also open to the sides of the cheek plates facing the rotor 18. The ports 61 and 63 are disposed the same radial distance from the rotor axis so that they register with the rotor slots 50 beneath both leading and trailing side inner ends 54 and 55 of the vanes 51.

The ports 61 and 63 are arcuately dimensioned so that both ends 54 and 55 of successive vanes 51 will be subject to, respectively, inlet suction and discharge pressure for the period during which both leading and trailing side bevels 52 and 53 are subject to, respectively, inlet suction and discharge pressure. As the vanes move from these areas, the leading and trailing bevels 52 and 53 will be subjected to different pressures. The inner vane ends 54 and 55 are therefore made subject to corresponding pressures by means of arcuate grooves 64 and 65 connected with the ports 61 respectively at outer and inner radial edges thereof, and arcuate grooves 66 and 67 connected with the ports 63 respectively at outer and inner radial edges thereof.

It will be seen, on reference to FIG. 5, that the leading and trailing side inner ends 54 and 55 of the vanes 51 will be subjected to the same respective pressures as are elfective on the leading and trailing side outer bevels 52 and 53 at all times throughout pump operation, thus completely balancing the vanes end to end at all times.

Although I have described only one preferred embodiment of my invention, it will be apparent to anyone skilled in the art that various changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim: I

1. A vane type fluid pump comprising (a) a housing having a pumping chamber, and an inlet and outlet open to spaced portions of said chamber,

(b) a rotor in said chamber and carrying vanes operable to pump fluid from said inlet to said outlet, (c) each of said vanes having a beveled outer portion and a stepped inner portion to define outer leading and trailing ends and inner leading and trailing ends, and

(d) means directing pressure from said outlet to said trailing end when said outer trailing end is subjected to outlet pressure, from said outlet to said leading inner end when said leading outer end is subjected to outlet pressure, from said inlet to said inner trailing end when said outer trailing end is subjected to inlet pressure, and from said inlet to said inner leading end when said outer leading end is subjected to inlet pressure.

2. The pump as defined in claim 1 and having cheek plates disposed on opposite faces of said rotor, said pressure directing means comprising passages in said cheek plates registering With spaces under the inner ends of said vanes.

3. The pump as defined in claim 1 and having cheek plates disposed on opposite faces of said rotor, said pressure directing means comprising,

(a) ports in said cheek plates each registering with spaces under both said leading and said trailing inner ends of successive vanes when both said leading and trailing outer ends are subjected to the same pressure, and

(b) arcuate grooves extending from the radially outer and inner edegs of said ports and arranged to register with the spaces in said leading and said trailing inner ends of said vanes when said leading and trailing outer ends are subject to different pressures and to thereby at all times subject the inner ends to pressures corresponding to the pressures effective on the outer ends of said vanes.

References Cited by the Examiner UNITED STATES PATENTS 983,754 2/1911 Nichols 91--136 2,473,309 6/ 1949 Stephens 103-136 2,545,238 3/1951 MacMillin et al 103136 2,919,651 1/1960 Gardiner 103136 3,099,964 8/1963 Eickmann 103136 3,102,494 9/1963 Adams 103136 FOREIGN PATENTS 53,868 6/1912 Austria. 152,123 10/1955 Sweden.

SAMUEL LEVINE, Primary Examiner.

JOSEPH H. BRANSON, JR., DONLEY J. STOCKING,

Examiners.

R. M. VARGO, Assistant Examiner. 

1. A VANE TYPE FLUID PUMP COMPRISING (A) A HOUSING HAVING A PUMPING CHAMBEAR, AND AN INLET AND OUTLET OPEN TO SPACED PORTIONS OF SAID CHAMBER, (B) A ROTOR IN SAID CHAMBER AND CARRYING VANES OPERABLE TO PUMP FLUID FROM SAID INLET TO SAID OUTLET, (C) EACH OF SAID VANES HAVING A BEVELED OUTER PORTION AND A STEPPED INNER PORTION TO DEFINE OUTER LEADING AND TRAILING ENDS AND INNER LEADING AND TRAILING ENDS, AND (D) MEANS DIRECTING PRESSURE FROM SAID OUTLET TO SAID TRAILING END WHEN SAID OUTER TRAILING END IS SUBJECTED TO OUTLET PRESSURE, FROM SAID OUTLET TO SAID LEADING INNER END WHEN SAID LEADING OUTER END IS SUBJECTED TO OUTLET PRESSURE, FORM SAID INLET TO SAID INNER TRAILING END WHEN SAID OUTER TRAILING END IS SUBJECTED TO INLET PRESSURE, AND FROM SAID INLET TO SAID INNER LEADING END WHEN SAID OUTER LEADING END IS SUBJECTED TO INLET PRESSURE. 